The present invention relates to an electromechanical transducer.
Electromechanical transducers are known which convert an electrical signal into a reversible deformation of a piezoelectric transducer element and also allow a conversion of a force into an electrical signal.
Piezoelectric transducer elements are known, which convert an electrical signal into a change in shape of the transducer element. This type of transducer element has many applications so that, for example, electrical relays can be made using piezoelectric transducers. Also Braille-Modules using piezoelectric transducer elements for making type characters or other symbols in Braille are known.
A piezoelectric relay is described in European Patent Application EP 0 067 883 A1, in which electrical contacts are attached to the piezoelectric transducer element which are moved by applying an electrical potential to the transducer element because the transducer element is deformed or bends on application of the electrical potential. A piezoelectric relay, in which a longitudinal extension of the transducer element is used to operate the electric contacts is described in European Patent Application EP 0 170 858 A1.
A piezoelectric module for producing type characters or symbols detectable by touch in Braille is described in U.S. Pat. No. 4,283,178. This piezoelectric module has pins detectable by touch on the free ends of piezoelectric transducer elements, which can be in two states, a raised state in which they are detectable by touch(set) and a lowered state(erased). The displacement of the piezoelectric transducer element occurs, because an electrical potential is applied to it.
The Braille Module is used to produce character-oriented information so that it can be read by a blind person. The Braille writing used is made up of a plurality of Braille characters which are made by a symbol specific combination of point-like elevations arranged in a 2.times.3 or 2.times.4 matrix. The spacing between the point-like elevations in the Braille character is smaller than the spacing between adjacent Braille characters. Module constructed Braille characters can be used as an output medium for a personal computer output unit. However no raphical information such as diagrams can be displayed or converted with this kind of type character-oriented output medium in the form of lines of type characters.